Sand Flap Work Piece Finishing Tool

ABSTRACT

Disclosed is a tool for finishing a work piece where the tool includes multiple pieces of abrasive material (sandpaper) mounted to a cylindrical housing and carrying a shank for mounting the tool to a portable electric drill or drill press or bench motor. The drill is powered to rotate the shank and housing in a first direction and the sheets of abrasive material are mounted at spaced locations around the periphery of the housing and wrapped in an opposite direction to the direction of rotation of the shank and housing, The sheet of abrasive material is cut from the end opposite to the attached end to form a plurality of finger-like projections which are not secured but tend to move outward when the housing is rotated. The fingers provide a yieldable abrasive surface which can adapt to the contours of the work piece and allow for finishing an irregular work piece.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a tool for finishing a work piece. Moreparticularly, the present invention related to a tool which carriesabrasive material and is rotated to remove burrs (or similarimperfections) from a work piece, such as a wooden spindle, dowel orsimilar member.

2. Background Art

Various sanding and burr-removal tools are known in the trade. Some areself-contained machinery (such as a grinding machine or a belt sander)and others are mounted on a large machine (such as a floor-mountedgrinder, a bench motor or a drill press). Unfortunately, neither ofthese types of tools is suitable for a home shop or a small operationwhere the worker may prefer to have something which is relativelyinexpensive and attaches to a hand-held rotating tool which he alreadyhas (such as a portable electric drill).

Examples of some of such tools for working on a work piece may be seen,inter alia, in U.S. Pat. Nos. 5,752,876; 6,190,246; 6,506,100; and6,001,009.

Some of these systems are large and costly and others requirespecialized machinery which may not be available to a worker in a homeshop or small scale operation.

Accordingly, it will be seen that these prior art systems for removingimperfections in a work piece have undesirable features and limitations.

SUMMARY OF THE INVENTION

The present invention overcomes some of the disadvantages andlimitations of the prior art systems and tools while providing a simple,yet effective, tool for removing burrs and irregularities from a workpiece. Such a work piece might be made from wood in some applicationsand other material, such as metals, alloys or plastics, in otherapplications. Think of a wooden dowel or spindle as one work piece whichmight be cut roughly from a blank and have resulting burrs andimperfections along its exposed surface, which may be curved, havecorners, or have other features which make removing the burrs and/orimperfections difficult and/or time-consuming for a hobbyist or a workerin his home shop. Despite the curves, corners or other geometric shapes,it is desired to have a smooth surface on the work piece, so a sandingfunction is desired. Hand sanding is slow, tedious and expensive, butusing a machine can damage the work piece and/or remove desired featuresof the work piece.

The present invention is a sanding tool which can be attached, in oneembodiment, to the chuck assembly of a conventional portable drill, thekind that any home shop might have. This sanding tool has a shank whichis of conventional size and shape for attachment to a conventional drill(the size of the shank may be ¼ inch or ⅜ inch, for example, a sizewhich would fit into most conventional home-use portable drills and berotated by the motor within the drill). This tool can be easily insertedinto the drill, as desired, and removed from the drill when the workpiece has been finished to the desired smoothness. The tool can be movedeasily when assembled into the drill into a desired location andorientation with respect to the work piece by the operator and movedalong a length of the work piece, if desired.

This tool includes a plurality of small finger-like projecting pieces ofsandpaper which tend to fly out as the tool is rotated in the directionopposite to the direction of mounting of the sandpaper, creating anappearance of the sandpaper fingers flapping, so this device has beencalled a “sand flap”. That is, the sheet(s) of sandpaper has beenwrapped around a cylindrical core in a clockwise direction, then theassembly is rotated in a counterclockwise direction for use of the tool.

The present tool has a rounded body mounted to the shaft and alignedgenerally with the shank for mounting it to the drill and carries apiece of sandpaper which has been cut into a plurality of elongatedsegments which are generally rectangular and extend outwardly from therounded body as it rotates. The elongated segments may be only partiallyseparated from a sheet of sandpaper which has been mounted to therounded body. The piece of sandpaper is mounted to the rounded body inone direction (for example, clockwise) with respect to the axis of therounded body, then is rotated in the opposite direction (in thisexample, counterclockwise) with respect to the rounded body by the drillin order to cause the segments to tend to move away from the body due tothe centrifugal force from the rotation of the body. As the segmentsmove away from the rounded body, they are brought into contact with thework piece in order to provide a yielding contact between the sandpaperand the work piece and remove burrs and imperfections.

Of course, many variations and adaptations are possible to the preferredembodiment of the present invention, and some of the features of thepresent invention may be used without the corresponding use of otherfeatures. Accordingly, the present document seeks to describe apreferred embodiment of the present invention with some particularityand some alternatives which are thought to be within the scope of thepresent invention and allow those of ordinary skill in the present artto make additional changes and adaptations to the invention as theymight envision. Based upon the teachings of this invention many changescan be made to the present invention without departing from its spirit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the sand flap tool of the presentinvention;

FIG. 2 is an end view of the sand flap tool of FIG. 1;

FIG. 3 is an end view of the sand flap tool of FIG. 2 in a time-lapsephotographic representation of the tool of FIG. 2 as it is rotated; and

FIG. 4 is a perspective view of a sand flap tool of the presentinvention working on a work piece.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, the sand flap tool 10 of the present inventionincludes a housing 20 mounted to a shank 30. The housing 20 preferablyhas a cylindrical shape and includes a sheet of sandpaper 40 mounted toit. The sheet of abrasive material (which may be thought of as sandpaperor a similar material) 40 has a rectangular shape to start, then one endof the sheet is attached to the round external surface of thecylindrical housing 20 and an opposite end of the sheet is cut to definea plurality of finger-like projections 42 extending from the sheet 40 atthe other end from the end secured to the housing. In one embodiment,each of the finger-like projections 42 is approximately the same width,or about 3/16 of an inch, and each finger is defined by short (perhaps1.25 inches) cut that extends generally parallel to each other andaligned generally with a transverse edge (of the rectangular sheet 40)that connects the end which is attached to the surface and the oppositeend with the finger-like projections 42.

The rectangular sheet of sandpaper 40 with the finger-like projections42 is secured at one end to the housing 20 and is wound in a firstdirection (shown by arrow A1) around the housing 20, forming a generallyspiral side view of the abrasive material. In one configuration of thepresent invention, the cylindrical housing 20 (and the mounted piece ofsandpaper) has a length of approximately 3 inches and the sheet ofsandpaper is divided into 16 finger-like projections of approximatelythe same width of 3/16 of an inch, although the fingers could be ofsomewhat greater or lesser size. While a single sheet of sandpaper 40could be used, an assembly having a plurality of sheets of sandpaper 40mounted spaced around the circumference of the cylinder could also beused to advantage. For example, if eighteen pieces of sandpaper areused, then one piece of sandpaper is mounted every 20 degrees around thecircumference of the cylindrical housing 20, allowing the process offinishing or sanding to progress faster.

The shank 30 is a conventional tool shank of the type conventionallyused to secure working tools within a chuck of a rotating tool such as aconvention electric portable hand drill (not shown) or a drill press orsimilar rotating tool. Although many of such electric hand drills areknown which operate to rotate a tool in a forward direction or a reversedirection, the preferred rotation for the drill or similar tool is shownby a second arrow A2, a direction which is oppose to the direction whicheach sheet of sandpaper 40 has been mounted to the cylindrical housing20. In this way, the ends 44 of the finger-like projections 42 are urgedoutwardly by centrifugal force of the rotating housing when the tool(e.g., the portable hand drill, not shown) is operated to rotate thehousing 20 in the direction of the arrow A2.

FIG. 2 is an end view of the sand flap tool 10 discussed in connectionwith FIG. 1 above, taken from the right hand side of the tool in FIG. 1.This view shows the several pieces of sandpaper are spiraled around thehousing 20. These piece of sandpaper or abrasive material arerepresented by the reference numerals 40 a, 40 b, 40 c, 40 d, . . . 40 qand 40 r. The exact number of these pieces of sandpaper is somewhat amatter of design choice (it is believed that the present invention wouldwork, albeit slowly, with a single sheet of sandpaper). In any event,each sheet of abrasive material is secured to the housing at one end andthe other end is free. Thus, the piece of abrasive material 40 a has afree end 42 a and an opposed end 46 a which is secured to the housing20. Because this is an end view, one cannot see the plurality of cutsalong the length of the sheet or the individual finger-like projectionscreated by the plurality of cuts.

FIG. 3 is another end view of the sand flap tool 10 of the presentinvention, in an orientation similar to that of FIG. 2 but includingsome representations of “time-lapse” photography as the tool 10 isrotate, e.g., by a user's electric drill, not shown in its preferreddirection of rotation shown by the arrows A2. One such sheet of abrasivematerial is represented by the reference numeral 40 a 1 at a given pointin time. The location of that same sheet at three previous times isrepresented by the reference numerals 40 a 2, 40 a 3 and 40 a 4. Othersheets have similar representations, with the current position of asecond sheet 40 b 1 also showing the location of that sheet at threeprevious times as well, by the reference numerals 40 b 2, 40 b 3 and 40b 4.

FIG. 4 shows the use of the sand flap tool 10 of the present inventionto work on a work piece 50. An end surface 52 of the work piece 50 mayhave burrs or other imperfections s. In some applications, the workpiece 50 may be made from wood and the process which formed the workpiece—whether sawing, milling or other processing, may leaveimperfections such as burrs which might snag or otherwise bedisadvantageous. The sand flap tool 10 is rotated in the direction ofthe arrow A2 by a suitable drive (such as a portable electric drill, notshown, held by an operator). This rotation of the tool 10 cases thefinger-like projections (the end of the sheet farthest away from theattachment of the sheet to the housing 30) to fan out due to centrifugalforce on the ends of the sheet. However, where the work piece is broughtinto contact with the sand flap tool 10, those ends are compressed andprovide a polishing or sanding action on the end surface 52 of the workpiece 50. The force of the work piece 50 on a section of the sand tool10 causes those finger-like projections 42 to compress and adds to theforce applied by the abrasive sheet onto the work piece. Typically thereis relative movement of the work piece 50 with respect to the sand flaptool 10, a movement which is shown by the arrow F indicating that thework piece 50 is moved toward the tool 10; it will be appreciated that asimilar arrangement can be obtained by moving the tool 10 into the workpiece 50, as might be the case where the work piece 50 is held in a viceor other suitable jig and the tool is moved by moving the portableelectric drill (not shown) which is rotating the sand flap tool 10.

The present design uses the abrasive action of sheets of sandpaper, butit will be appreciated that much of the work (the abrading) will beaccomplished with the outer portions of the sandpaper, and the amount ofsanding or polishing will decrease as one moves inwardly from the outeredge of the sandpaper sheet, so that there will be little to no use ofthe sandpaper located well in from the outer edge. For this reason—andto obtain additional use from a given amount of sandpaper—it may bedesirable to remove the outer edges of the sandpaper after the tool hasbeen used for some time and the grit on the outer edges has become wornand less effective. Accordingly, the user may cut off the outer mostends of the finger-like projections at this point and continue to usethe shortened pieces of sandpaper with a better supply of abrasivematerial. In some cases, it may be desirable to score such sandpaper tofacilitate the remove of the leading edge of the sheet and expose an endwhich has better supply of abrasive.

Of course, many modifications and adaptations of the preferredembodiment shown in the accompanying drawings and described above arepossible without departing from the spirit of the present inventionwhich is defined solely by the claims which follow. For example, while acylindrical housing is desirable in some applications, another shape(such as an oval shaped housing, or a housing with a contour chosen tomatch the contour of a work piece to be worked) could be used toadvantage in some situations. Also, for some work pieces, it might bedesirable to have multiple cylindrical housings of different diametersattached together, for example, to work on a work piece with a largerportion and a smaller portion. While the finger-like projections mightbe formed with slits which are general parallel with each other andspaced equal distant from the adjoining projection, the present designdoes not require that the finger-like projections all be of similar sizeor shape, and in some cases it may be desirable to have thinnerprojections in one portion of the tool for finer polishing and a widerprojection in other portions for coarser working of the work piece.Further, it may be desirable to use some of the features of the presentinvention without the corresponding use of other features. In somecases, it may be desirable to use a shank which is bent or flexible toallow the working on a work piece to occur with an orientation which isnot an extension of the shank. Accordingly, it will be apparent that thepresent invention may be altered in many ways without departing from thespirit of the invention.

Having thus described the invention, what is claimed is:
 1. A tool forremoving portions of a work piece, said tool comprising: A shank forinsertion into a tool and adapted to be rotated in a first direction; Acylindrical housing attached to the shank, the axis of the cylindricalhousing being generally aligned with the shank and the housing coupledto the shank to be rotated along with the shank in the first direction;and A plurality of sheets of abrasive material mounted to thecylindrical housing and wrapped in a direction opposite to the firstdirection, at least some of the sheets of abrasive material beingpartially cut to form elongated fingers of abrasive material.
 2. A toolof the type described in claim 1 wherein the elongated fingers areformed by generally parallel cuts to form rectangular fingers.
 3. A toolof the type described in claim 2 wherein the elongated fingers areapproximately the same size.
 4. A tool of the type described in claim 1wherein the plurality of sheets of abrasive material are spaced evenlyaround the periphery of the cylindrical housing.
 5. A tool of the typedescribed in claim 4 wherein the fingers formed in each sheet ofabrasive material are the same size.
 6. A method of making a tool forremoving imperfections from a work piece, the steps of the methodcomprising: Providing an elongated shank member which is adapted toreceive a rotational force to rotate it in a first direction; Mountingto the elongated shank a housing having a rounded portion, the roundedportion having an axis which is generally aligned with the elongatedshank and rotates with the shank; Providing multiple sheets of abrasivematerial with cuts to define a plurality of elongated fingers extendingfrom a base on each sheet; and Mounting the base of each sheet ofabrasive material to the rounded housing and wrapping the sheets ofabrasive material with their elongated fingers in a direction oppositeto the first direction.
 7. A method including the steps set forth inclaim 6 wherein the step of providing the sheets of abrasive materialincludes the step of cutting elongated fingers of approximately the samesize into each sheet of abrasive material.
 8. A method including thesteps of claim 6 wherein the step of providing the sheets of abrasivematerial includes the step of cutting approximately parallel cuts alonga length of the abrasive sheet to form elongated fingers having asubstantially uniform width.
 9. A method including the steps of claim 6wherein the step of mounting each sheet of abrasive material includesthe step of mounting each sheet at approximately the same distance fromthe preceding sheet so that the sheets are uniformly mounted around theperiphery of the rounded portion.